1. © 2007 Pearson Education DD DD GG GG GG MM MM MM AA AA L LL LL LL L Process Layout Chapter 8

2. © 2007 Pearson Education Layout Planning  Layout planning is planning that involves decisions about the physical arrangement of economic activity centers needed by a facility’s various processes.  Layout plans translate the broader decisions about the competitive priorities, process strategy, quality, and capacity of its processes into actual physical arrangements.  Economic activity center: Anything that consumes space -- a person or a group of people, a customer reception area, a teller window, a machine, a workstation, a department, an aisle, or a storage room.

3. © 2007 Pearson Education Before a manager can make decisions regarding physical arrangement, four questions must be addressed. 1.What centers should the layout include? 2.How much space and capacity does each center need? 3.How should each center’s space be configured? 4.Where should each center be located? Layout Planning Questions

4. © 2007 Pearson Education Facility Layout Defined Facility layout can be defined as the process by which the placement of departments, workgroups within departments, workstations, machines, and stock- holding points within a facility are determined This process requires the following inputs:  Specification of objectives of the system in terms of output and flexibility  Estimation of product or service demand on the system  Processing requirements in terms of number of operations and amount of flow between departments and work centers  Space requirements for the elements in the layout  Space availability within the facility itself 7A-4

5. © 2007 Pearson Education Process Layout: Interdepartmental Flow  Given  The flow (number of moves) to and from all departments  The cost of moving from one department to another  The existing or planned physical layout of the plant  Determine  The “best” locations for each department, where best means maximizing flow, which minimizing costs 7A-5

6. © 2007 Pearson Education Process Layout: Systematic Layout Planning  Numerical flow of items between workcenters  Can be impractical to obtain  Does not account for the qualitative factors that may be crucial to the placement decision  Systematic Layout Planning  Accounts for the importance of having each department located next to every other department  Is also guided by trial and error  Switching workcenters then checking the results of the “closeness” score 7A-6

7. © 2007 Pearson Education Strategic Issues  Layout choices can help communicate an organization’s product plans and competitive priorities.  Altering a layout can affect an organization and how well it meets its competitive priorities in the following ways: 1.Increasing customer satisfaction and sales at a retail store. 2.Facilitating the flow of materials and information. 3.Increasing the efficient utilization of labor and equipment. 4.Reducing hazards to workers. 5.Improving employee morale. 6.Improving communication.

8. © 2007 Pearson Education Performance Criteria  Customer satisfaction  Level of capital investment  Requirements for materials handling  Ease of stockpicking  Work environment and “atmosphere”  Ease of equipment maintenance  Employee and internal customer attitudes  Amount of flexibility needed  Customer convenience and levels of sales

9. © 2007 Pearson Education Types of Layouts  Flexible-flow layout: A layout that organizes resources (employees) and equipment by function rather than by service or product.  Line-flow layout: A layout in which workstations or departments are arranged in a linear path.  Hybrid layout: An arrangement in which some portions of the facility have a flexible-flow and others have a line-flow layout.  Fixed-position layout: An arrangement in which service or manufacturing site is fixed in place; employees along with their equipment, come to the site to do their work.

10. © 2007 Pearson Education A Flexible (process oriented) Flow Layout Foundry Milling machines LathesGrinding PaintingDrills Office Welding Forging A job shop has a flexible-flow layout.

11. © 2007 Pearson Education Process-Oriented Layout  Like machines and equipment are grouped together  Flexible and capable of handling a wide variety of products or services  Scheduling can be difficult and setup, material handling, and labor costs can be high

12. © 2007 Pearson Education Process-Oriented Layout  Arrange work centers so as to minimize the costs of material handling  Basic cost elements are  Number of loads (or people) moving between centers  Distance loads (or people) move between centers

13. © 2007 Pearson Education Office Layout  Grouping of workers, their equipment, and spaces to provide comfort, safety, and movement of information  Movement of information is main distinction  Typically in state of flux due to frequent technological changes

14. © 2007 Pearson Education Example of Systematic Layout Planning: Importance of Closeness Value A E I O U X Closeness Line code Numerical weights Absolutely necessary Especially important Important Ordinary closeness OK Unimportant Undesirable 16 8 4 2 0 80 7A-14

15. © 2007 Pearson Education Relationship Chart Figure 9.1

16. © 2007 Pearson Education Fixed-Position Layout  Product remains in one place  Workers and equipment come to site  Complicating factors  Limited space at site  Different materials required at different stages of the project  Volume of materials needed is dynamic

17. © 2007 Pearson Education Line Flow (product oriented) Layout Station 1Station 2Station 3Station 4 A production line has a line-flow layout.

18. © 2007 Pearson Education McDonald’s Assembly Line Figure 9.12

19. © 2007 Pearson Education Product-Oriented Layout 1.Volume is adequate for high equipment utilization 2.Product demand is stable enough to justify high investment in specialized equipment 3.Product is standardized or approaching a phase of life cycle that justifies investment 4.Supplies of raw materials and components are adequate and of uniform quality Organized around products or families of similar high-volume, low-variety products

20. © 2007 Pearson Education Product-Oriented Layouts 1.Low variable cost per unit 2.Low material handling costs 3.Reduced work-in-process inventories 4.Easier training and supervision 5.Rapid throughput Advantages 1.High volume is required 2.Work stoppage at any point ties up the whole operation 3.Lack of flexibility in product or production rates Disadvantages

21. © 2007 Pearson Education Comparison of Product vs. Product Layouts Process Layouts Product Layouts Products: large #, different small # efficiently Resources: general purpose specialized Facilities: more labor intensive more capital intensive Flexibility: greater relative to market lower relative to market Processing slower faster Rates: Handling costs: high low Space requirements: higher lower

22. © 2007 Pearson Education Assembly Line Balancing  Line balancing is the assignment of work to stations in a line so as to achieve the desired output rate with the smallest number of workstations.  Work elements are the smallest units of work that can be performed independently.  Immediate predecessors are work elements that must be done before the next element can begin.  Precedence diagram allows one to visualize immediate predecessors better; work elements are denoted by circles, with the time required to perform the work shown below each circle.

23. © 2007 Pearson Education Assembly Line Balancing  Step 1: Identify tasks & immediate predecessors  Step 2: Determine the desired output rate  Step 3: Calculate the cycle time  Step 4: Compute the theoretical minimum number of workstations  Step 5: Assign tasks to workstations (balance the line)  Step 6: Compute efficiency, idle time & balance delay

24. © 2007 Pearson Education Assembly Line Balancing 1.Precedence diagram: circles=tasks, arrows show the required sequence. 2.Determine cycle time: 3.Determine required workstations (theoretical minimum) 4.Set rules for assigning tasks (number of following tasks, longest task time)

25. © 2007 Pearson Education Assembly Line Balancing 5.Assign tasks to first workstation, using rules and staying within cycle time. Repeat for following workstations until all tasks are assigned. 6.Evaluate line efficiency: 7.Rebalance if efficiency is not satisfactory.

26. © 2007 Pearson Education Step 1: Identify Tasks & Immediate Predecessors

27. © 2007 Pearson Education Layout Calculations  Step 2: Determine output rate  Vicki needs to produce 60 pizzas per hour  Step 3: Determine cycle time  The amount of time each workstation is allowed to complete its tasks  Limited by the bottleneck task (the longest task in a process):

28. © 2007 Pearson Education Layout Calculations (continued)  Step 4: Compute the theoretical minimum number of stations  TM = number of stations needed to achieve 100% efficiency (every second is used)  Always round up (no partial workstations)  Serves as a lower bound for our analysis

29. © 2007 Pearson Education Layout Calculations (continued)  Step 5: Assign tasks to workstations  Start at the first station & choose the longest eligible task following precedence relationships  Continue adding the longest eligible task that fits without going over the desired cycle time  When no additional tasks can be added within the desired cycle time, begin assigning tasks to the next workstation until finished

30. © 2007 Pearson Education Last Layout Calculation  Step 6: Compute efficiency and balance delay  Efficiency (%) is the ratio of total productive time divided by total time  Balance delay (%) is the amount by which the line falls short of 100%

31. © 2007 Pearson Education Example 8.3 Line Balancing Example 8.3 Green Grass, Inc., a manufacturer of lawn & garden equipment, is designing an assembly line to produce a new fertilizer spreader, the Big Broadcaster..

32. © 2007 Pearson Education Using the information in the previous slide, answer the following questions: 1.Construct a Precedence diagram 2.If the company would like to product 60 units per hour determine cycle time: 5.Determine required workstations (theoretical minimum) 6.Assign tasks to workstations 7.Calculate line efficiency:

33. © 2007 Pearson Education Green Grass, Inc. Line Balancing Green Grass, Inc. 6 E 20 H 18 I 40 D 30 B 25 F 50 C 40 A 15 G ABolt leg frame to hopper40None BInsert impeller shaft 30A CAttach axle50A DAttach agitator40B EAttach drive wheel6B FAttach free wheel25C GMount lower post15C HAttach controls20D, E IMount nameplate18F, G Total244 Work Time Immediate ElementDescription (sec) Predecessor(s)

34. © 2007 Pearson Education Application 8.3

35. © 2007 Pearson Education Using the information in the previous slide, answer the following questions: 1.Construct a Precedence diagram 2.If the company would like to product 60 units per hour determine cycle time: 5.Determine required workstations (theoretical minimum) 6.Assign tasks to workstations 7.Calculate line efficiency:

36. © 2007 Pearson Education Solved Problem 2

37. © 2007 Pearson Education Solved Problem 2 Precedence Diagram 20 E 145 H 130 I 25 D 80 B 15 F 50 C 40 A 120 G 115 J

38. © 2007 Pearson Education Solved Problem 2 Line Balancing Process

39. © 2007 Pearson Education Solved Problem 2 Line Balancing Solution 20 E 145 H 130 I 25 D 80 B 15 F 50 C 40 A 120 G 115 J S1 S4 S2 S5 S3